We are sorry to hear that there maybe a problem with your mattress.
As the product is not yet 12 months old then your contract of sale is with the retailer and in the first instance you should contact them.
We test our beds using a 200kg roller (31.5 stones). The weight is rolled across the mattress 20,000 times to assess general durability of the mattress. However, this weight is always moving on the mattress and not left stationary